<template>
  <div>
  <router-link tag="div" to="/" class="header-abs" v-show="showAbs">
    <div class="iconfont header-abs-back">&#xe624;</div>
  </router-link>
  <div class="header-fixed"  v-show="!showAbs" :style="opacityStyle">
    <router-link to="/">
      <div class="iconfont header-fixed-back">&#xe624;</div>
    </router-link>
    景点详情
  </div>
  </div>
</template>
<script>
export default {
  name: 'DetailHeader',
  data () {
    return {
      showAbs: true,
      opacityStyle: {
        opacity: 0
      }
    }
  },
  methods: {
    handleScroll () {
      const top = document.documentElement.scrollTop
      if (top > 60) {
        const opacity = top / 140
        this.opacity = opacity > 1 ? 1 : opacity
        this.opacityStyle = {opacity}
        this.showAbs = false
      } else {
        this.showAbs = true
      }
    }
  },
  activated () {
    window.addEventListener('scroll', this.handleScroll)
  },
  deactivated () {
    window.removeEventListener('scroll', this.handleScroll)
  }
}
</script>
<style lang="stylus" scoped>
  @import "~styles/varibles.styl"
  .header-abs
    position: absolute
    top: .2rem
    left: .2rem
    border-radius: .4rem
    line-height: .8rem
    background: rgba(0,0,0,.8)
    text-align: center
    height: .8rem
    width: .8rem
    .header-abs-back
      font-size: .4rem
      color: #ffffff
  .header-fixed
    z-index: 2
    position: fixed
    top: 0
    left: 0
    right: 0
    height: $headerHeight
    line-height: $headerHeight
    text-align: center
    color: #ffffff
    background: $bgColor
    .header-fixed-back
      position: absolute
      top: 0
      left: 0
      width: .64rem
      text-align: center
      color: #ffffff
      font-size: .4rem
</style>
